Typically, automatic and manual operation of movable barriers, such as garage doors or gates, has included a gear system which allows for easy movement of a barrier. Many developments in the gate operator industry have transformed movable barriers, including the implementation of various kinds of motors and gear systems to operate one or more gates. For example, in the past, movable barrier systems have included AC induction motors, DC brush motors, and DC brushless motors.
One of the problems encountered in the gate operator industry is controlling actuation to achieve smooth, efficient, and effective operation of movable barriers. The current practice, which utilizes motors such as AC induction motors, must implement various complex systems of gears and electronics in order to provide the adequate amount of power at the correct speed.
For example, systems with conventional motors usually include phase control mechanisms to monitor and alter the frequency of voltage applied to the motor—furthermore these motors fail to provide high torque at low speeds. DC brush motors present the advantage that speed may be controlled in a linear fashion in relation to the voltage applied, however, these motors lose the desired torque at very low speeds. And although DC brushless motors also provide the same speed control, the DC brushless motor also fails to provide the desired high torque at very low speeds.
The gate operation industry has therefore implemented the use of a gear box or a belt system to accomplish the torque required to move a particular barrier. These complex systems seek to regulate smooth actuation but remain inadequate to retain linear control of speed while optimizing the correct amount of torque necessary to perform a particular task.
Adding belts, chains or gear boxes increases the volume of the system, adding more moving parts and essentially additional variables for possible system malfunctions. Manufacturers in the gate operation industry have attempted to alleviate this problem but those methods remain inadequate for the following reasons.
Some manufacturers have tried to implement c-phase mounting techniques between a motor and the gear box, however, this method raises the possibility of oil or grease leakage that may damage a gate operating system.
Other manufacturers have tried to minimize the number of components in a gate operating system by implementing a motor-gear head device to minimize potential problems during assembly. However, gear boxes, with oil or grease that may eventually leak, are still required and thus present the problem of potential damage and higher maintenance requirements.
Alternatively, other manufacturers have implemented a planetary gear system in their designs. This gear system presents the advantage of very small gearing capable of providing high torque, however, their need for oil or grease still requires higher maintenance to prevent damage from its lubricants.
Yet perhaps the most significant problem presented by the use of gear systems is the fact that gear systems do not provide 100% efficiency. In fact, it is commonly known in the industry that such gearing systems provide efficiency levels raging from 40% to 90% depending on the quality of the system used; notably, the more efficient gear systems are costly.
Due to the inadequate methods and systems used to operate movable barriers (particularly in industrial applications), the gate operation industry is flooded with gate operators that are large, heavy, and complex—which require relatively large motors and big gear boxes. For these reasons and others, the prior art has been inadequate to suit the needs of gate operator users, installers and manufacturers.
Therefore, there is a need in the art for a system that utilizes fewer components to achieve higher precision actuation of movable barriers without complex gear systems and electronics. It is desirable to develop a movable barrier operator that contains fewer parts to minimize maintenance and potential malfunctions, while retaining the desired control of the operator at low speeds and generating the desired high torque during actuation. It is to these ends that the present invention has been developed.